1. Field of the Invention
The present invention relates to cargo security systems, and more particularly to a security system for the protection of cargo located in an enclosed compartment of a vehicle such as a truck which indicates that the vehicle cargo area may have been accessed by opening the door to the cargo compartment during transit.
2. Description of Prior Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Currently, it is very common for trucks used to transport cargo to utilize a plastic or metal seal attached to the handle of the latch of the access door of the cargo compartment. The physical seal is attached by the shipper after the truck is loaded with the cargo and the cargo door has been closed, before the truck leaves the shipper to travel to its destination.
In order to open the truck door and access the cargo, it is necessary to move the latch handle which requires the seal to be removed. Thus, the physical seal acts as a visual indicator as to whether the access door to the cargo compartment has been opened during transit. At the destination, the recipient observes the physical seal when the truck arrives, before the vehicle door is opened. If the seal remains intact, the recipient knows that the cargo access door has not been opened and thus the cargo has not been tampered with during transit. If the seal is broken, the recipient knows that the cargo access door may have been opened, permitting access to the cargo and thus may not accept the shipment.
However, the physical seal has an inherent disadvantage. Since it is exposed to the elements during transit, it is subject to being damaged or broken for reasons other than accessing the cargo, causing the shipper to refuse the shipment even though the cargo may be intact.
In order to provide a more reliable way of determining whether cargo is secure during transit, an improved digital vehicle cargo security system was invented and is the subject of U.S. Pat. No. 8,004,393, issued Aug. 23, 2011. The patented system includes a digital counter having a display. The number on the counter is automatically set after the cargo area is secured by the latch being moved to the position where the truck bed is engaged by the J-hook to keep the access door of the cargo compartment closed
The system senses if the latch is moved to disengage the J-hook, meaning that the cargo area may have been accessed after the cargo area was secured, and causes the number on the counter to change in response. The original number set on the counter by the shipper is forwarded to the destination by shipping documents, the internet or any other means. At the destination, it can be determined if the cargo area may have been accessed in transit by comparing the original number and the number displayed on the counter when the vehicle reaches the destination location.
The patented digital vehicle cargo security system functions well and is currently used on many vehicles. However, it requires a custom designed lock to replace the latch which is provided at the factory by the vehicle manufacturer. The custom lock is designed to be mounted on the exterior of the cargo door and must be strong enough to prevent tampering or attack. It therefore requires a thick metal housing which adds substantial weight to the vehicle door.
There is a need for a simpler, less expensive, highly reliable vehicle security system which can work with the factory supplied latch and thus does not require an expensive, heavy custom replacement lock.